Bulk solids heat exchanger

ABSTRACT

A heat exchanger has a housing that includes an inlet for receiving bulk solids, and an outlet for discharging the bulk solids. A plurality of heat transfer tubes are disposed between the inlet and the outlet and extend generally transversely in the housing, and are arranged in rows such that the heat transfer tubes in a row of the rows are generally parallel and are spaced apart to facilitate the flow of bulk solids through the spaces between the heat transfer tubes. Supports are disposed in the housing, between the plurality of heat transfer tubes and the outlet, for supporting the plurality of heat transfer tubes thereon. The rows of heat transfer tubes are stacked in contact with adjacent rows of heat transfer tubes such that heat transfer tubes of a first row of the stack are in contact with and are supported by the supports and heat transfer tubes of each subsequent row of the stack are in contact with and supported by a previous row of the stack.

FIELD OF THE INVENTION

The present disclosure relates to heat exchangers for cooling high temperature bulk solids.

BACKGROUND

Heat exchangers may utilize air or other gas for cooling bulk solids as the bulk solids flow through the heat exchanger. The use of air or other gas for heat exchange with solids is inefficient and does not lend itself to recovering the heat into a working fluid for use in energy applications such as energy capture and energy storage.

Heat transfer plates or tubes provide improved efficiency in heat exchangers by indirect heat exchange with bulk solids that flow, under the force of gravity, through the heat exchanger. The heat transfer plates or tubes include a fluid flowing through the plates or tubes and the bulk solids are heated or cooled as they flow through spaces between adjacent heat transfer plates or tubes.

Such heat exchange systems are generally utilized in relatively low temperature heat exchange applications but are unsuitable for high temperature applications due to limitations of the heat transfer plates and tubes.

Improvements to heat exchangers are desirable.

SUMMARY

According to one aspect of an embodiment, a heat exchanger has a housing including an inlet for receiving bulk solids, and an outlet for discharging the bulk solids. A plurality of heat transfer tubes are disposed between the inlet and the outlet and extend generally transversely in the housing. Supports are disposed in the housing, between the plurality of heat transfer tubes and the outlet, for supporting the plurality of heat transfer tubes thereon. Heat transfer tubes of the plurality of heat transfer tubes are in contact with adjacent heat transfer tubes such that a first heat transfer tube is supported on at least one of the supports, a second heat transfer tube is in contact with and supported by the first heat transfer tube, and a third heat transfer tube is in contact with and supported by the second heat transfer tube.

According to another aspect of an embodiment, a heat exchanger has a housing that includes an inlet for receiving bulk solids, and an outlet for discharging the bulk solids. A plurality of heat transfer tubes are disposed between the inlet and the outlet and extend generally transversely in the housing, and are arranged in rows such that the heat transfer tubes in a row of the rows are generally parallel and are spaced apart to facilitate the flow of bulk solids through the spaces between the heat transfer tubes. Supports are disposed in the housing, between the plurality of heat transfer tubes and the outlet, for supporting the plurality of heat transfer tubes thereon. The rows of heat transfer tubes are stacked in contact with adjacent rows of heat transfer tubes such that heat transfer tubes of a first row of the stack are in contact with and are supported by the supports and heat transfer tubes of each subsequent row of the stack are in contact with and supported by a previous row of the stack.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be described, by way of example, with reference to the drawings and to the following description, in which:

FIG. 1 is a perspective view of a heat exchanger for heat exchange with high temperature bulk solids, in accordance with an embodiment;

FIG. 2A is a perspective view of the groups of heat transfer tubes of the heat exchanger of FIG. 1;

FIG. 2B is an alternative perspective view of the groups of heat transfer tubes of the heat exchanger of FIG. 1;

FIG. 3 is an exploded perspective view of the heat transfer tubes of the heat exchanger of FIG. 1; and

FIG. 4 is a sectional view of the heat transfer tubes of the heat exchanger of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

For simplicity and clarity of illustration, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. Numerous details are set forth to provide an understanding of the embodiments described herein. The embodiments may be practiced without these details. In other instances, well-known methods, procedures, and components have not been described in detail to avoid obscuring the embodiments described. The description is not to be considered as limited to the scope of the embodiments described herein.

The disclosure generally relates to a heat exchanger having a housing that includes an inlet for receiving bulk solids, and an outlet for discharging the bulk solids. A plurality of heat transfer tubes are disposed between the inlet and the outlet and extend generally transversely in the housing, and are arranged in rows such that the heat transfer tubes in a row of the rows are generally parallel and are spaced apart to facilitate the flow of bulk solids through the spaces between the heat transfer tubes. Supports are disposed in the housing, between the plurality of heat transfer tubes and the outlet, for supporting the plurality of heat transfer tubes thereon. The rows of heat transfer tubes are stacked in contact with adjacent rows of heat transfer tubes such that heat transfer tubes of a first row of the stack are in contact with and are supported by the supports and heat transfer tubes of each subsequent row of the stack are in contact with and supported by a previous row of the stack.

FIG. 1 shows a perspective view of an embodiment of a heat exchanger 100. The heat exchanger 100 includes the housing 102 that has a generally rectangular cross-section. The housing 102 includes an inlet 104 at a top thereof for introducing bulk solids into the heat exchanger 100. The inlet 104 includes a cover 106 to cover the opening of the inlet 104 and to provide a generally enclosed environment in the heat exchanger 100. The bulk solids may be, for example, ceramic beads, sintered bauxite, sand, or any other suitable solids that are introduced to the heat exchanger 100 at a temperature in the range of about 1000° C. to about 500° C. The residence time of the bulk solids in the heat exchanger may be about 15 minutes or greater. The bulk solids may be cooled in the heat exchanger 100 to a temperature in the range of about 100° C. to about 500° C. The heat exchanger 100 includes a withdrawal system 108 to control the flow of bulk solids from the heat exchanger 100 and out the outlet 110 through which the cooled bulk solids are discharged from the housing 102 of the heat exchanger 100.

The withdrawal system 108 may be any suitable bulk solid withdrawal system for controlling the flow of the bulk solids, such as an oszillomat available from Geroldinger GmbH. The cover 106 and the withdrawal system 108, with the bulk solids introduced, together provide a generally closed environment in the housing 102 for heat exchange with the bulk solids.

Reference is now made to FIG. 2A and FIG. 2B, with continued reference to FIG. 1. A plurality of heat transfer tubes 202 are disposed within the housing 102, between the inlet 104 and the withdrawal system 108 shown in FIG. 1.

Thus, the rows of heat transfer tubes 202 are stacked in contact with adjacent rows of heat transfer tubes 202. The heat transfer tubes 202 of a final row of the stack are in contact with and are supported by supports 230 within the housing and each of the heat transfer tubes 202 of a subsequent row in the stack is in contact with and is supported by the heat transfer tubes 202 of a previous row of the stack to reduce bending stress on the heat transfer tube 202, for example, when bulk solids are introduced into the heat exchanger 100.

In the example shown in FIG. 2A through FIG. 4, the heat transfer tubes 202 are constructed in rows that are arranged and constructed in three groups 204, 206, 208. Each of the groups 204, 206, 208 is associated with a respective inlet manifold 210, 212, 214, and a respective outlet manifold 216, 218, 220. The heat transfer tubes 202 include heat transfer tubes 222 of the first group 204, heat transfer tubes 224 of the second group 206, and heat transfer tubes 226 of the third group 208.

Referring to the exploded view of the heat transfer tubes of FIG. 3, a first inlet manifold 210 is coupled to a first row 302 of the heat transfer tubes 222 of the first group 204 and to a second row 304 of the heat transfer tubes 222 of the first group 204 and is utilized to distribute heat exchange fluid to the heat transfer tubes 222 of the first row 302 and the second row 304 of the first group 204. A first outlet manifold 216 is coupled to the last two rows 326, 328 of the heat transfer tubes 222 of the first group 204 and receives heat exchange fluid therefrom.

As shown in FIG. 3, the first group 204 of heat transfer tubes 222 includes 14 rows 302, 304, 306, 308, 310, 312, 314, 316, 318, 320, 322, 324, 326, 328 of heat transfer tubes 222. Each row of the 14 rows 302, 304, 306, 308, 310, 312, 314, 316, 318, 320, 322, 324, 326, 328 of heat transfer tubes 222 of the first group 204 includes 14 tubes that are spaced apart and extend generally parallel to each other. Each heat transfer tube 222 of the first group 204 has a first end 332 near a first side of the housing 102 and a second end 334 near an opposing, second side of the housing 102. Thus, each heat transfer tube 222 of the first group 204 extends generally laterally across the housing 102, which is transverse to a major axis of the housing 102 and transverse to the direction of flow of the bulk solids.

The first inlet manifold 210 is fluidly coupled to every other heat transfer tube 222 of the first row 302. In this example, the first inlet manifold 210 is coupled by respective fluid coupling lines 330 to a first end 302 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222 of the first row 302. The first inlet manifold 210 is disposed outside and near the first side of the housing 102 and the fluid coupling lines 330 extend inwardly through the first side of the housing 102. The second end 334 of each of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222 of the first row 302 is coupled to the second end 334 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222, respectively, of the first row 302 by a respective 180° pipe elbow 336. Thus, the heat transfer tube 222 of the first row 302 is fluidly coupled to the adjacent, heat transfer tube 222 of the first row 302 by one of the 180° pipe elbows 336.

The first end 332 of each of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222 of the first row 302 is coupled by a respective pipe coupling 338 to a first end 332 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222, respectively, of the third row 306 of heat transfer tubes 222 of the first group 204. A second end 334 of each second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222 of the first row 302 is coupled by a respective 180° pipe elbow 336 to the second end 334 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222, respectively, of the third row 306 of heat transfer tubes 222 of the first group 204.

The first end 332 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222 of the third row 306 of heat transfer tubes 222 of the first group 204 is coupled by a respective pipe coupling 338 to a first end 332 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222, respectively, of the fifth row 310. A second end 334 of each first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222 of the fifth row 310 is coupled by a respective 180° pipe elbow 336 to the second end 334 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222, respectively, of the fifth row 310 of heat transfer tubes 222 of the first group 204.

The first end 332 of each of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222 of the fifth row 310 is coupled by a respective pipe coupling 338 to a first end 332 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222, respectively, of the seventh row 314 of heat transfer tubes 222 of the first group 204. A second end 334 of each second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222 of the seventh row 314 is coupled by a respective 180° pipe elbow 336 to the second end 334 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222, respectively, of the seventh row 314 of heat transfer tubes 222 of the first group 204.

The first end 332 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222 of the seventh row 314 of heat transfer tubes 222 of the first group 204 is coupled by a respective pipe coupling 338 to a first end 332 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222, respectively, of the ninth row 318. A second end 334 of each first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222 of the ninth row 318 is coupled by a respective 180° pipe elbow 336 to the second end 334 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222, respectively, of the ninth row 318 of heat transfer tubes 222 of the first group 204.

The first end 332 of each of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222 of the ninth row 318 is coupled by a respective pipe coupling 338 to a first end 332 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222, respectively, of the eleventh row 322 of heat transfer tubes 222 of the first group 204. A second end 334 of each second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222 of the eleventh row 322 is coupled by a respective 180° pipe elbow 336 to the second end 334 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222, respectively, of the eleventh row 322 of heat transfer tubes 222 of the first group 204.

The first end 332 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222 of the eleventh row 322 of heat transfer tubes 222 of the first group 204 is coupled by a respective pipe coupling 338 to a first end 332 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222, respectively, of the thirteenth row 326. A second end 334 of each first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222 of the thirteenth row 326 is coupled by a respective 180° pipe elbow 336 to the second end 334 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222 of the thirteenth row 326 of heat transfer tubes 222, respectively, of the first group 204.

The first end 332 of each of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222 of the thirteenth row 326 is fluidly coupled to the first outlet manifold 216 by respective fluid discharge lines 340. The first outlet manifold 216 is disposed outside and near the first side of the housing 102 and the fluid discharge lines 340 extend through the first side of the housing 102.

The first inlet manifold 210 is also fluidly coupled to every other heat transfer tube 222 of the second row 304. In this example, the first inlet manifold 210 is coupled by respective fluid coupling lines 330 to a first end 302 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222 of the second row 304. The second end 334 of each of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222 of the first row 302 is coupled to the second end 334 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222, respectively, of the second row 304 by a respective 180° pipe elbow 336.

The first end 332 of each of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222 of the second row 304 is coupled by a respective pipe coupling 338 to a first end 332 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222, respectively, of the fourth row 308 of heat transfer tubes 222 of the first group 204. A second end 334 of each first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222 of the second row 302 is coupled by a respective 180° pipe elbow 336 to the second end 334 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222, respectively, of the fourth row 308 of heat transfer tubes 222 of the first group 204.

The first end 332 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222 of the fourth row 308 of heat transfer tubes 222 of the first group 204 is coupled by a respective pipe coupling 338 to a first end 332 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222, respectively, of the sixth row 312. A second end 334 of each second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222 of the sixth row 312 is coupled by a respective 180° pipe elbow 336 to the second end 334 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222, respectively, of the sixth row 312 of heat transfer tubes 222 of the first group 204.

The first end 332 of each of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222 of the sixth row 312 is coupled by a respective pipe coupling 338 to a first end 332 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222, respectively, of the eighth row 316 of heat transfer tubes 222 of the first group 204. A second end 334 of each first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222 of the eighth row 302 is coupled by a respective 180° pipe elbow 336 to the second end 334 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222, respectively, of the eighth row 316 of heat transfer tubes 222 of the first group 204.

The first end 332 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222 of the eighth row 316 of heat transfer tubes 222 of the first group 204 is coupled by a respective pipe coupling 338 to a first end 332 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222, respectively, of the tenth row 320. A second end 334 of each second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222 of the tenth row 320 is coupled by a respective 180° pipe elbow 336 to the second end 334 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222, respectively, of the tenth row 320 of heat transfer tubes 222 of the first group 204.

The first end 332 of each of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222 of the tenth row 320 is coupled by a respective pipe coupling 338 to a first end 332 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222, respectively, of the twelfth row 324 of heat transfer tubes 222 of the first group 204. A second end 334 of each first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222 of the twelfth row 324 is coupled by a respective 180° pipe elbow 336 to the second end 334 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222, respectively, of the twelfth row 324 of heat transfer tubes 222 of the first group 204.

The first end 332 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222 of the twelfth row 324 of heat transfer tubes 222 of the first group 204 is coupled by a respective pipe coupling 338 to a first end 332 of the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222, respectively, of the fourteenth row 328. A second end 334 of each second, fourth, sixth, eighth, tenth, twelfth, and fourteenth heat transfer tube 222 of the fourteenth row 328 is coupled by a respective 180° pipe elbow 336 to the second end 334 of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tube 222, respectively, of the fourteenth row 328 of heat transfer tubes 222 of the first group 204.

The first end 332 of each of the first, third, fifth, seventh, ninth, eleventh, and thirteenth heat transfer tubes 222 of the fourteenth row 328 is also fluidly coupled to the first outlet manifold 216 by respective fluid discharge lines 340.

Thus, the heat transfer tubes 222 of the first group 204 are all coupled directly or indirectly to the first inlet manifold 210 and the heat transfer tubes 222 of the first group 204 are all coupled directly or indirectly to the first outlet manifold 216 to facilitate the flow of heat exchange fluid through each of the heat transfer tubes of the first group. The heat exchange fluid flows from the first inlet manifold 210, horizontally and through a switchback in a row, then flows vertically upwardly to the next but one row within the first group 204, skipping the next row of the first group 204, as well as four rows of the third group 208 and two rows of the second group 206. The heat exchange fluid continues to flow horizontally, through a horizontal switch back, and then skipping vertically upwardly until the heat exchange fluid flows out to the first outlet manifold 216.

Similarly, a second inlet manifold is coupled to a first row of the heat transfer tubes 224 of the second group 206 and to a second row of the heat transfer tubes 224 of the second group 206 and is utilized to distribute heat exchange fluid to the heat transfer tubes 224 of the first row and the second row of the second group 206. A second outlet manifold 218 is coupled to the last, or top, two rows of the heat transfer tubes 224 of the second group 206 and receives heat exchange fluid therefrom.

The second group 206 of heat transfer tubes 224 also includes 14 rows. Each row of the 14 rows of heat transfer tubes 224 of the second group 206 includes 14 tubes that are spaced apart and extend generally parallel to each other. Each heat transfer tube 224 of the second group 206 has a first end near the second side of the housing 102 and has a second end near the first side of the housing 102. Thus, each heat transfer tube 224 of the second group 206 extends generally laterally across the housing 102 which is transverse to a major axis of the housing 102 and transverse to the direction of flow of the bulk solids.

The second group 206 is arranged and constructed similar to the first group 204 and many of the elements are not described in detail again for the purpose of simplicity and clarity.

Similar to the first group 204, the second inlet manifold 212 is fluidly coupled to every other heat transfer tube 224 of the first row of the second group 206 and to every other heat transfer tube 224 of the second row of the second group 206. Each heat transfer tube 224 of the first row is fluidly coupled to an adjacent heat transfer tube 224 in the first row and each heat transfer tube 224 of the second row is fluidly coupled to an adjacent heat transfer tube 224 in the second row, utilizing 180° pipe elbows.

The second outlet manifold 218 is fluidly coupled to every other heat transfer tube 224 of the thirteenth row of the second group 206 and to every other heat transfer tube 224 of the fourteenth row of the second group 206. Each heat transfer tube 224 of each row of the second group 206 is fluidly coupled to an adjacent heat transfer tube in the same row.

Thus, the heat transfer tubes 224 of the second group 206 are all coupled directly or indirectly to the second inlet manifold 212 and the heat transfer tubes 224 of the second group 206 are all coupled directly or indirectly to the second outlet manifold 218 to facilitate the flow of heat exchange fluid through each of the heat transfer tubes of the second group 206. Similar to the first group 204, the heat exchange fluid flows in the second group 206, from the second inlet manifold 212, horizontally and through a horizontal switchback in a row, then flows vertically upwardly to the next but one row, thus skipping the next row of the second group 206, as well as four rows of the third group 208 and two rows of the first group 204. The heat exchange fluid continues to repeatedly flow horizontally, horizontally switching back, and then skipping vertically upwardly until the heat exchange fluid flows out to the second outlet manifold 218.

The second inlet manifold 212 is disposed outside and near the second side of the housing 102 and the fluid coupling lines 330 from the second inlet manifold 212 extend inwardly through the second side of the housing 102. The second outlet manifold 218 is disposed outside and near the second side of the housing 102 and the fluid discharge lines 340 to the second outlet manifold 218 extend through the second side of the housing 102. Thus, the first inlet manifold 210 and first outlet manifold 216 are disposed on an opposite side of the housing 102 as the second inlet manifold 212 and the second outlet manifold 218. The heat transfer tubes 222 of the first group 204 extend generally parallel to the heat transfer tubes 224 of the second group 206.

A third inlet manifold 214 is coupled to a first row of the heat transfer tubes 226 of the third group 208 and to a second row of the heat transfer tubes 226 of the third group 208 and is utilized to distribute heat exchange fluid to the heat transfer tubes 226 of the first row and the second row of the third group 208. A third outlet manifold 220 is coupled to the last two rows of the heat transfer tubes 226 of the third group 208 and receives heat exchange fluid therefrom. The third inlet manifold 214 is disposed outside and near a third side of the housing 102 and the fluid coupling lines from the third inlet manifold 214 extend inwardly through the third side of the housing 102. The third outlet manifold 220 is disposed outside and near the third side of the housing 102 and the fluid discharge lines to the third outlet manifold 220 extend through the third side of the housing. The third side of the housing 102 extends from the first side to the second side. Thus, respective inlet and outlet manifolds are disposed near three of the four sides of the housing 102.

The third group 208 of heat transfer tubes 226 includes 28 rows. Each row of the 28 rows of heat transfer tubes 226 of the third group 208 includes 21 tubes that are spaced apart and extend generally parallel to each other. Each heat transfer tube 226 of the third group 208 has a first end near a third side of the housing 102 and has a second end near a fourth side of the housing 102. Each heat transfer tube 226 of the third group 208 extends generally laterally across the housing 102, and generally perpendicular to the direction that the heat transfer tubes 222 of the first group 204 and the heat transfer tubes 224 of the second group 206 extend. The heat transfer tubes 226 of the third group 208 extend transverse to a major axis of the housing 102 and transverse to the direction of flow of the bulk solids.

Unlike the first group 204 and the second group 206, the heat transfer tubes 226 in the rows of the third group 208 are not coupled to respective adjacent heat transfer tubes 226 in the same row. Each of the heat transfer tubes 226 in the first row and in the second row of the third group are directly coupled at a first end thereof, by fluid coupling lines, to the third inlet manifold 214. Each heat transfer tube 226 in the first row is coupled by a pipe coupling 338, at a second end of the heat transfer tubes 226, to a respective heat transfer tube 226 in the third row. Each heat transfer tube 226 in the third row is coupled by a pipe coupling, at a first end of the heat transfer tubes 226, to a respective heat transfer tube 226 in the fifth row. Each heat transfer tube 226 in the fifth row is coupled to a respective heat transfer tube 226 in the seventh row, and so on as each heat transfer tube 226 of the third group 208 is coupled to a respective heat transfer tube 226 in the next but one row. The third outlet manifold 220 is coupled by fluid discharge lines to the heat transfer tubes 226 in the twenty-seventh and twenty-eighth rows of the third group 208, and receives heat exchange fluid therefrom.

The heat exchange fluid flows in the third group 208, from the third inlet manifold 214, horizontally along a heat transfer tube 226, and then flows vertically upwardly to the next but one row, thus, skipping the next row of the heat transfer tubes 226 of the third group 208. The heat exchange fluid continues to flow horizontally and then skipping vertically until the heat exchange fluid flows out to the third outlet manifold 220. When flowing through the group of heat transfer tubes 226, the heat exchange fluid does not flow through horizontal switchbacks. Thus, the heat exchange fluid flows from the third inlet manifold 214, in a serpentine manner through the heat transfer tubes 226, and out to the third outlet manifold 220.

Referring now to FIG. 4, with continued reference to FIG. 1 through 3, a respective row of heat transfer tubes 226 of the third group 208 extends between and in contact with adjacent rows of the heat transfer tubes 222 of the first group 204 and the heat transfer tubes 224 of the second group 206 and generally at right angles thereto to form a layered structure of heat transfer tubes 202. Every second layer of the layered structure is a row of heat transfer tubes 226 of the third group 208 such that the heat transfer tubes 202 extend generally transversely in the housing, in alternating layers extending generally perpendicular to each other.

Thus, a top layer of heat transfer tubes 202 includes the fourteenth row 328 of heat transfer tubes 222 of the first group 204. The top layer, which is the fourteenth row 328 of heat transfer tubes 222 of the first group 204, is in contact with and supported by a final row, which is the twenty-eighth row of heat transfer tubes 226, of the third group 208. The heat transfer tubes 222 of the fourteenth row 328 of the first group 204 are in contact with and supported by the heat transfer tubes 226 of the third group 208, at spaced apart locations along the lengths of the heat transfer tubes 226 of the third group 208. The heat transfer tubes 226 of the second layer, which includes the heat transfer tubes 226 of the final row of the third group 208, are in contact with and supported, at spaced apart locations, by a third layer of heat transfer tubes 202, which includes heat transfer tubes 222 of the thirteenth row 326 of the first group 204. The heat transfer tubes 222 of the thirteenth row 326 of the first group 204 are in contact with and supported, at spaced apart locations, by the twenty-seventh row of heat transfer tubes 226 of the third group 208. The heat transfer tubes 226 of the twenty-seventh row of the third group 208 are in contact with and supported, at spaced apart locations, by a fourteenth row of heat transfer tubes 224 of the second group 206, which are in contact with and supported by, at spaced apart locations, a twenty-sixth row of heat transfer tubes 226 of the third group 208. The stack continues with all 56 rows of heat transfer tubes 202 from the three groups 204, 206, 208. The bottom row of heat transfer tubes 202 is supported on a set of supports 230 (as shown in FIG. 2B) that extend the length of the heat transfer tubes 202 of the bottom row in the stack.

Thus, the rows of heat transfer tubes 202 are stacked in contact with vertically adjacent rows of heat transfer tubes 202 such that heat transfer tubes 202 of a bottom row of the stack are in contact with and are supported by the supports 230 and each subsequent row of heat transfer tubes 202 in the stack are in contact with and are supported by a previous row of the stack. Each heat transfer tube 202 is supported at a plurality of spaced apart locations along the length of the heat transfer tube 202 to reduce bending stress on the heat transfer tube 202, for example, when bulk solids are introduced into the heat exchanger 100. With such support, high pressure fluid, such as supercritical CO₂, may be utilized to facilitate capture of the heat during cooling of high temperature bulk solids that are introduced into the inlet, flow between the heat transfer tubes 202, through the withdrawal system 108, and out the outlet 106.

As described above, the first and second groups 204, 206 each include 14 rows of heat transfer tubes and the heat exchange fluid flows horizontally through switchbacks followed by vertically skipping upwardly. The third group 208 includes 28 rows and does not include horizontal switchbacks. With this arrangement, the overall length and the number of bends in each flow path is similar, regardless of which group the tubes of the flow path are in. Utilizing a similar flow path length and similar number of bends in the flow path results in generally equivalent pressure drops through the flow paths and thus substantially equal distribution of heat transfer fluid in each group of tubes, facilitating balanced heat duty and temperature change in heat exchange fluid in each flow path.

Each of the first group 204, second group 206, and third group 208 of heat transfer tubes may be separately fabricated and then inserted together to provide the single stack of heat transfer tubes. In addition, the first group 204 and the second group 206 may be separated out from the sides of group 208 after the stack is assembled for the purpose of maintenance or repair, and then reinserted to provide the stack.

The heat transfer tubes 202 may be any suitable size and any suitable alloy to facilitate heat transfer from the bulk solids to the heat exchange fluid and to withstand the temperatures of the bulk solids and pressures of the heat exchange fluid, which may be, for example, supercritical CO₂. The heat transfer tubes 202 may be 1.37 cm outside diameter pipe, 6.03 cm outside diameter pipe, or any other suitable size pipe.

The terms top, bottom, horizontal, and vertical are utilized herein to provide reference to the orientation of the heat exchanger 100 when assembled for use, as shown in FIG. 1. The term heat transfer tube is utilized herein to refer to a conduit through which fluid may flow. The heat transfer tube 202 is not limited to a cylindrical tube that has a circular cross-section. Any other suitable shape to facilitate fluid flow there through may be utilized.

The fluid coupling lines 330 and fluid discharge lines 340 extend through sides of the housing 102. As indicated above, the first outlet manifold 216 is disposed outside and near the first side of the housing 102 and the fluid coupling lines 330 to the heat transfer tubes 222 of the first group 204 and fluid discharge lines 340 from the heat transfer tubes 222 of the first group 204 extend through the first side of the housing 102. The second inlet manifold 212 is disposed outside and near the second side of the housing 102 and the fluid coupling lines 330 to the heat transfer tubes 224 of the second group 206 and the fluid discharge lines 340 from the heat transfer tubes 224 of the second group 206 extend through the second side of the housing 102. The third inlet manifold 214 is disposed outside and near the third side of the housing 102 and the fluid coupling lines 330 to the heat transfer tubes 226 of the third group 208 and the fluid discharge lines 340 from the heat transfer tubes 226 of the third group 208 extend through the third side of the housing 102.

The fluid coupling lines 330 and the fluid discharge lines 340 extend through the housing 102 in such a way to facilitate movement of the heat transfer tubes 202 within the housing 102 while providing a seal with the housing.

The operation of the heat exchanger 100 will now be described with reference to FIG. 1. When bulk solids are fed into the housing 102, through the inlet 104, the bulk solids flow downwardly as a result of the force of gravity from the inlet 104 into and through spaces between the heat transfer tubes 202. The bulk solids that contact the heat transfer tubes 202 are generally deflected into the spaces between the tubes. As the bulk solids flow between the heat transfer tubes 202, the bulk solids are cooled and heat is transferred to the heat exchange fluid that flows through the heat transfer tubes. The heat exchange fluid generally flows horizontally and upwardly, while the bulk solids generally flow downwardly in the housing 102. The heat exchange fluid that flows through the heat transfer tubes 202 indirectly cools the bulk solids and is utilized to capture the energy, in the form of heat, from the bulk solids as the bulk solids are cooled.

The bulk solids then flow through the withdrawal system 108, which controls the flow of bulk solids from the heat exchanger 100, and out the outlet 110 through which the bulk solids are discharged from the housing 102 of the heat exchanger 100.

The heat transfer tubes are effectively interlaced with a bottom row of tubes supported on the supports 230 and each subsequent row of heat transfer tubes in contact with and supported on a respective previous row. Advantageously, supporting each heat transfer tube at various locations along the length thereof reduces bending stresses on each heat transfer tube by comparison to the bending stress on such a tube when the tube is not supported at various locations along the length. Thus, the bending stress is reduced when high temperature bulk solids are introduced into the heat exchanger for indirect heat exchange and the use of a suitable heat exchange fluid at high pressure is facilitated.

In the above-described embodiments, the orientation of the heat transfer tubes alternates such that adjacent layers of heat transfer tubes extend generally perpendicularly to each other. Other arrangements of heat transfer tubes may be successfully implemented, however. For example, the heat transfer tubes may, alternatively, be stacked on each other in a parallel arrangement such that the heat transfer tubes are generally parallel to each other and are supported along the full length of each heat transfer tube. Thus, the heat transfer tubes are stacked in contact with vertically adjacent heat transfer tubes. The heat transfer tubes at the bottom of the stack are in contact with and are supported by supports within the housing and each of the heat transfer tubes above those tubes at the bottom of the stack, are in contact with and supported substantially along the entire length by the heat transfer tubes below.

The heat exchange fluid that flows through the heat transfer is utilized to capture the energy, in the form of heat, from the bulk solids as the bulk solids are cooled. Thus, the energy from the bulk solids is captured and may be utilized or stored. The heat may be recovered from the heat exchange fluid, for example, for input to a turbine for electricity for a grid.

The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole. All changes that come with meaning and range of equivalency of the claims are to be embraced within their scope. 

1. A heat exchanger comprising: a housing including an inlet for receiving bulk solids, and an outlet for discharging the bulk solids; a plurality of heat transfer tubes disposed between the inlet and the outlet and extending generally transversely in the housing; supports disposed in the housing, between the plurality of heat transfer tubes and the outlet, for supporting the plurality of heat transfer tubes thereon; wherein heat transfer tubes of the plurality of heat transfer tubes are in contact with adjacent heat transfer tubes such that a first heat transfer tube is supported on at least one of the supports, a second heat transfer tube is in contact with and supported by the first heat transfer tube, and a third heat transfer tube is in contact with and supported by the second heat transfer tube.
 2. The heat exchanger according to claim 1, wherein the second heat transfer tube is supported by more than one of the plurality of heat transfer tubes, including the first heat transfer tube.
 3. The heat exchanger according to claim 2, wherein the second heat transfer tube is supported at a plurality of spaced apart locations along the length of the second heat transfer tube.
 4. The heat exchanger according to claim 1, wherein the second heat transfer tube extends generally perpendicular to the first heat transfer tube.
 5. The heat exchanger according to claim 4, wherein the third heat transfer tube extends generally parallel to the first heat transfer tube.
 6. The heat exchanger according to claim 1, wherein the first, second, and third heat transfer tubes are generally parallel to each other.
 7. The heat exchanger according to claim 1, wherein each of the plurality of heat transfer tubes includes a passage for the flow of a heat exchange fluid therethrough.
 8. The heat exchanger according to claim 1, comprising a plurality of manifolds coupled to the plurality of heat transfer tubes.
 9. A heat exchanger comprising: a housing including an inlet for receiving bulk solids, and an outlet for discharging the bulk solids; a plurality of heat transfer tubes disposed between the inlet and the outlet and extending generally transversely in the housing, and arranged in rows such that the heat transfer tubes in a row are generally parallel and are spaced apart to facilitate the flow of bulk solids through the spaces between the heat transfer tubes; supports disposed in the housing, between the plurality of heat transfer tubes and the outlet, for supporting the plurality of heat transfer tubes thereon; wherein rows of heat transfer tubes are stacked in contact with adjacent rows of heat transfer tubes such that heat transfer tubes of a first row of the stack are in contact with and are supported by the supports and heat transfer tubes of each subsequent row of the stack are in contact with and supported by a previous row of the stack.
 10. The heat exchanger according to claim 9, wherein the rows of heat transfer tubes are arranged such that the heat transfer tubes of each row of the stack extend generally transversely to the heat transfer tubes of the adjacent row of the stack.
 11. The heat exchanger according to claim 10, wherein the heat transfer tubes of the subsequent row are supported at multiple, spaced apart locations along the lengths of the heat transfer tubes, by the heat transfer tubes of the previous row.
 12. The heat exchanger according to claim 10, wherein each heat transfer tube of the subsequent row is supported by each of the heat transfer tubes of the previous row.
 13. The heat exchanger according to claim 9, wherein the heat transfer tubes of each row extend generally parallel to the heat transfer tubes of the adjacent row.
 14. The heat exchanger according to claim 9, wherein each of the plurality of heat transfer tubes includes a passage for the flow of a heat exchange fluid through the plurality of heat transfer tubes.
 15. The heat exchanger according to claim 14, comprising a plurality of manifolds coupled to the plurality of heat transfer tubes to distribute flow of heat exchange fluid into the heat transfer tubes.
 16. The heat exchanger according to claim 14, wherein the heat transfer tubes of rows in the stack are in fluid communication with the heat transfer tubes of other rows of the stack.
 17. The heat exchanger according to claim 16, comprising a plurality of inlet manifolds and a plurality of outlet manifolds coupled to the heat transfer tubes for flow of heat exchange fluid from the inlet manifolds, through the heat transfer tubes, and to the outlet manifold.
 18. The heat exchanger according to claim 9, comprising a withdrawal system disposed between the supports and the outlet for controlling the flow of bulk solids in the heat exchanger.
 19. The heat exchanger according to claim 18, wherein the withdrawal system provides a closed heat exchange system. 